| 摘要 |
<p>In a power supply circuit, comprising a rectifier unit (D) for rectifying an AC mains voltage (Vm), a thyristor (T) coupled across first and second outputs of the rectifier unit (D), and a thyristor control circuit (T1, T1', Rb) for controlling the thyristor (T) in such a manner, that the thyristor (T) is switched on when a voltage over the thyristor (T) is substantially zero, the thyristor control circuit (T1, T1', Rb) includes a transistor (T1, T1') having a main current path between a control terminal of the thyristor (T) and the first output of the rectifier unit, and a resistor (Rb) between a control terminal of the transistor (T1, T1') and the second output of the rectifier unit (D). <IMAGE></p> |
